High Power Room Temperature Emission Quantum Cascade Lasers at Lambda

We present two different techniques for processing InP-based λ = 9μm quantum cascade lasers which improve the thermal dissipation in the device. The first process is ba sed on hydrogen implantation creating an insulating layer to inject current selectively in one part of the active region. The sec ond process uses a thick electroplated gold layer on the laser ri dge to efficiently remove the heat produced in the active region. Each process is designed to improve heat evacuation leading to higher performances of the lasers and will be compared to a standard ridge structure from the same wafer. We give eviden ce that the process of proton implantation, efficient in GaAs based structures, is not directly applicable to InP based devicesand we present a detailed analysis of the thermal properties of dev ices with an electroplated gold thick layer. With these lasers, an average power of 174 mW at a duty cycle of 40% has been measured at 10◦C.